Transmission system for measured values in fire alarm system - with delay time preceding transmission characterising each detector (BE240177)

摘要

The transmission system is used for transmission of measured values, provided by a number of parallel fire detectors, to a central evaluation circuit (3) for the fire alarm network. All the parallel fire detectors (M) connected to a transmission line (L) are addressed cyclically with each detector (M) providing a current pulse whose duration represent the measured value, after a delay time characteristic of the respective detector (M). The evaluation circuit has means for measuring the delay times and the pulse durations, to record the measured values provided by the respective detectors. Pref. each detector (M) has an additional resistor in parallel with the transmission line (L) for providing the current pulse.